Choose the correct alternative from the following : - Assertion (A) : When common salt is kept open, it absorbs moisture from the air.
Reason (R) : Common salt contains magnesium chloride.

Answer: A. Both A and R are true and R is the correct explanation of A.

Magnesium chloride present in common salt is a deliquescent substance
i.e. it absorbs moisture from the air when kept in open.